U.S. Pat. No. 8,056,518, which is incorporated herein by reference in entirety, discloses a valve actuating system that determines a shape of its jam nut surface as a function of a resultant force on a ball stud exerted by a rocker arm on the ball stud during operation of the valve train. The contact surface of the jam nut, which is pressed against an associated surface of the head of an engine, is a conical surface with an included angle that is generally twice the magnitude of an angle between a resultant force on the ball stud and a central axis of the ball stud and its associated jam nut. Certain accommodations can be made in order to reduce the cost of the system that would occur if perfect mathematical preciseness with a most preferred embodiment of the present invention is employed.
U.S. Pat. No. 7,383,799, which is incorporated herein by reference in entirety, discloses a system for monitoring changes in the operation of a valve system of an engine. An accelerometer provides vibration-related signals that are obtained by a microprocessor or similarly configured device and compared to a reference or baseline magnitude. The obtaining step can comprise the steps of measuring, filtering, rectifying, and integrating individual data points obtained during specific windows of time determined as a function of the rotational position of the crankshaft of the engine. These windows in time are preferably selected as a function of the position of exhaust or intake valves as they move in response to rotation of cams of the valve system.